Add solution for Basic Select domain

Basic Select/10_weather_observation_station_5.sql

@@ -0,0 +1,25 @@
+(
+    SELECT
+        city,
+        LENGTH(city)
+    FROM
+        station
+    ORDER BY
+        LENGTH(city),
+        city
+    LIMIT
+        1
+)
+UNION
+    (
+        SELECT
+            city,
+            LENGTH(city)
+        FROM
+            station
+        ORDER BY
+            LENGTH(city) DESC,
+            city
+        LIMIT
+            1
+    );

Basic Select/11_weather_observation_station_6.sql

@@ -0,0 +1,19 @@
+-- USING LIKE
+SELECT
+    DISTINCT city
+FROM
+    station
+WHERE
+    city LIKE 'a%'
+    OR city LIKE 'e%'
+    OR city LIKE 'i%'
+    OR city LIKE 'O%'
+    OR city LIKE 'u%';
+
+-- USING REGEXP
+SELECT
+    DISTINCT city
+FROM
+    station
+WHERE
+    city REGEXP '^[a, e, i, o, u].*';

Basic Select/12_weather_observation_station_7.sql

@@ -0,0 +1,19 @@
+-- USING LIKE
+SELECT
+    DISTINCT city
+FROM
+    station
+WHERE
+    city LIKE '%a'
+    OR city LIKE '%e'
+    OR city LIKE '%i'
+    OR city LIKE '%o'
+    OR city LIKE '%u';
+
+-- USING REGEXP
+SELECT
+    DISTINCT city
+FROM
+    station
+WHERE
+    city REGEXP '.*[a, e, i, o, u]$';

Basic Select/13_weather_observation_station_8.sql

@@ -0,0 +1,16 @@
+-- USING REGEXP
+SELECT
+    DISTINCT city
+FROM
+    station
+WHERE
+    city REGEXP '^[a,e,i,o,u].*[a,e,i,o,u]$';
+
+-- USING STRING FUNCTION
+SELECT
+    DISTINCT city
+FROM
+    station
+WHERE
+    LEFT(city, 1) IN ('a', 'e', 'i', 'o', 'u')
+    and RIGHT(city, 1) IN ('a', 'e', 'i', 'o', 'u');

Basic Select/14_weather_observation_station_9.sql

@@ -0,0 +1,15 @@
+-- USING REGEXP
+SELECT
+    DISTINCT city
+FROM
+    station
+WHERE
+    city NOT REGEXP '^[a, e, i, o, u].*';
+
+-- USING STRING FUNCTIONS
+SELECT
+    DISTINCT city
+FROM
+    station
+WHERE
+    LEFT(city, 1) NOT IN ('a', 'e', 'i', 'o', 'u');

Basic Select/15_weather_observation_station_10.sql

@@ -0,0 +1,6 @@
+SELECT
+    DISTINCT city
+FROM
+    station
+WHERE
+    RIGHT(city, 1) NOT IN ('a', 'e', 'i', 'o', 'u');

Basic Select/16_weather_observation_station_12.sql

@@ -0,0 +1,7 @@
+SELECT
+    DISTINCT city
+FROM
+    station
+WHERE
+    LEFT(city, 1) NOT IN ('a', 'e', 'i', 'o', 'u')
+    AND RIGHT(city, 1) NOT IN ('a', 'e', 'i', 'o', 'u');

Basic Select/17_higher_than_75_marks.sql

@@ -0,0 +1,9 @@
+SELECT
+    name
+FROM
+    students
+WHERE
+    marks > 75
+ORDER BY
+    SUBSTRING(name, -3, 3),
+    id;

Basic Select/18_employee_names.sql

@@ -0,0 +1,6 @@
+SELECT
+    name
+FROM
+    employee
+ORDER BY
+    name;

Basic Select/19_employee_salaries.sql

@@ -0,0 +1,9 @@
+SELECT
+    name
+FROM
+    employee
+WHERE
+    (salary > 2000)
+    AND (months < 10)
+ORDER BY
+    employee_id;

Basic Select/1_revising_the_select_query_I.sql

@@ -0,0 +1,4 @@
+SELECT *
+FROM   city
+WHERE  countrycode = 'USA'
+       AND population > 100000; 

Basic Select/2_revising_the_select_query_II.sql

@@ -0,0 +1,4 @@
+SELECT NAME
+FROM   city
+WHERE  countrycode = 'USA'
+       AND population > 120000; 

Basic Select/3_select_all.sql

@@ -0,0 +1,2 @@
+SELECT *
+FROM   city; 

Basic Select/4_select_by_id.sql

@@ -0,0 +1,3 @@
+SELECT *
+FROM   city
+WHERE  id = 1661;

Basic Select/5_japanese_cities_attributes.sql

@@ -0,0 +1,3 @@
+SELECT *
+FROM   city
+WHERE  countrycode = 'JPN'; 

Basic Select/6_japanese_cities_names.sql

@@ -0,0 +1,6 @@
+SELECT
+    name
+FROM
+    city
+WHERE
+    countrycode = 'JPN';

Basic Select/7_weather_observation_station_1.sql

@@ -0,0 +1,5 @@
+SELECT
+    city,
+    state
+FROM
+    station;

Basic Select/8_weather_observation_station_3.sql

@@ -0,0 +1,6 @@
+SELECT
+    DISTINCT city
+FROM
+    station
+WHERE
+    id % 2 = 0;

Basic Select/9_weather_observation_station_4.sql

@@ -0,0 +1,12 @@
+SELECT
+    (
+        SELECT
+            COUNT(*)
+        FROM
+            station
+    ) - (
+        SELECT
+            COUNT(DISTINCT city)
+        FROM
+            station
+    );

README.md

@@ -14,25 +14,25 @@ The solutions to all the HackerRank SQL Track Challenges on MySQL Environment.
 
 |S.N.|Challenge |Solution|
 |----|----------|--------|
-|1.|[Revising the Select Query I](https://www.hackerrank.com/challenges/revising-the-select-query)||
-|2.|[Revising the Select Query II](https://www.hackerrank.com/challenges/revising-the-select-query-2)||
-|3.|[Select All](https://www.hackerrank.com/challenges/select-all-sql)||
-|4.|[Select By ID](https://www.hackerrank.com/challenges/select-by-id)||
-|5.|[Japanese Cities' Attributes](https://www.hackerrank.com/challenges/japanese-cities-attributes)||
-|6.|[Japanese Cities' Names](https://www.hackerrank.com/challenges/japanese-cities-name)||
-|7.|[Weather Observation Station 1](https://www.hackerrank.com/challenges/weather-observation-station-1)||
-|8.|[Weather Observation Station 3](https://www.hackerrank.com/challenges/weather-observation-station-3)||
-|9.|[Weather Observation Station 4](https://www.hackerrank.com/challenges/weather-observation-station-4)||
-|10.|[Weather Observation Station 5](https://www.hackerrank.com/challenges/weather-observation-station-5)||
-|11.|[Weather Observation Station 6](https://www.hackerrank.com/challenges/weather-observation-station-6)||
-|12.|[Weather Observation Station 7](https://www.hackerrank.com/challenges/weather-observation-station-7)||
-|13.|[Weather Observation Station 8](https://www.hackerrank.com/challenges/weather-observation-station-8)||
-|14.|[Weather Observation Station 9](https://www.hackerrank.com/challenges/weather-observation-station-9)||
-|15.|[Weather Observation Station 10](https://www.hackerrank.com/challenges/weather-observation-station-10)||
-|16.|[Weather Observation Station 12](https://www.hackerrank.com/challenges/weather-observation-station-12)||
-|17.|[Higher Than 75 Marks](https://www.hackerrank.com/challenges/more-than-75-marks)||
-|18.|[Employee Names](https://www.hackerrank.com/challenges/name-of-employees)||
-|19.|[Employee Salaries](https://www.hackerrank.com/challenges/salary-of-employees)||
+|1.|[Revising the Select Query I](https://www.hackerrank.com/challenges/revising-the-select-query)|[Solution](/Basic%20Select/1_revising_the_select_query_I.sql)|
+|2.|[Revising the Select Query II](https://www.hackerrank.com/challenges/revising-the-select-query-2)|[Solution](/Basic%20Select/2_revising_the_select_query_II.sql)|
+|3.|[Select All](https://www.hackerrank.com/challenges/select-all-sql)|[Solution](/Basic%20Select/3_select_all.sql)|
+|4.|[Select By ID](https://www.hackerrank.com/challenges/select-by-id)|[Solution](/Basic%20Select/4_select_by_id.sql)|
+|5.|[Japanese Cities' Attributes](https://www.hackerrank.com/challenges/japanese-cities-attributes)|[Solution](/Basic%20Select/5_japanese_cities_attributes.sql)|
+|6.|[Japanese Cities' Names](https://www.hackerrank.com/challenges/japanese-cities-name)|[Solution](/Basic%20Select/6_japanese_cities_names.sql)|
+|7.|[Weather Observation Station 1](https://www.hackerrank.com/challenges/weather-observation-station-1)|[Solution](/Basic%20Select/7_weather_observation_station_1.sql)|
+|8.|[Weather Observation Station 3](https://www.hackerrank.com/challenges/weather-observation-station-3)|[Solution](/Basic%20Select/8_weather_observation_station_3.sql)|
+|9.|[Weather Observation Station 4](https://www.hackerrank.com/challenges/weather-observation-station-4)|[Solution](/Basic%20Select/9_weather_observation_station_4.sql)|
+|10.|[Weather Observation Station 5](https://www.hackerrank.com/challenges/weather-observation-station-5)|[Solution](/Basic%20Select/10_weather_observation_station_5.sql)|
+|11.|[Weather Observation Station 6](https://www.hackerrank.com/challenges/weather-observation-station-6)|[Solution](/Basic%20Select/11_weather_observation_station_6.sql)|
+|12.|[Weather Observation Station 7](https://www.hackerrank.com/challenges/weather-observation-station-7)|[Solution](/Basic%20Select/12_weather_observation_station_7.sql)|
+|13.|[Weather Observation Station 8](https://www.hackerrank.com/challenges/weather-observation-station-8)|[Solution](/Basic%20Select/13_weather_observation_station_8.sql)|
+|14.|[Weather Observation Station 9](https://www.hackerrank.com/challenges/weather-observation-station-9)|[Solution](/Basic%20Select/14_weather_observation_station_9.sql)|
+|15.|[Weather Observation Station 10](https://www.hackerrank.com/challenges/weather-observation-station-10)|[Solution](/Basic%20Select/15_weather_observation_station_10.sql)|
+|16.|[Weather Observation Station 12](https://www.hackerrank.com/challenges/weather-observation-station-12)|[Solution](/Basic%20Select/16_weather_observation_station_12.sql)|
+|17.|[Higher Than 75 Marks](https://www.hackerrank.com/challenges/more-than-75-marks)|[Solution](/Basic%20Select/17_higher_than_75_marks.sql)|
+|18.|[Employee Names](https://www.hackerrank.com/challenges/name-of-employees)|[Solution](/Basic%20Select/18_employee_names.sql)|
+|19.|[Employee Salaries](https://www.hackerrank.com/challenges/salary-of-employees)|[Solution](/Basic%20Select/19_employee_salaries.sql)|
 ## Advanced Select
 
 |S.N.|Challenge |Solution|